<!DOCTYPE html>
<html lang="zh">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>DOM1</title>
    <style>
        .red{
            background: red;
        }
    </style>
</head>
<body>  
<div>
    <div id="test">
        <span>test1</span>
    <p class= "red">段落标签3</p>test2
    </div>
</div>
<div id="empty">
    <div id="e1"></div>
    <div id="e2"></div>
    <div id="e3"></div>
</div>

<div id="siblings">
    <div id="s1"></div>
    <div id="s2"></div>
    <div id="s3"></div>
</div>
<div id="travel">
    <div id="t1">t1</div>
    <div id="t2">t2</div>
    <div id="t3">t3</div>
</div>   

<script src= "dom.js" ></script>
<script src="main.js"></script>
</body>
</html>